package load

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"

	"git.asio.asia/nixevol/NixMsg/test/harness"
)

const maxImportRows = 1000

type apiEnvelope struct {
	OK    bool           `json:"ok"`
	Data  map[string]any `json:"data"`
	Error *struct {
		Code    string `json:"code"`
		Message string `json:"message"`
	} `json:"error"`
}

// Provision 按配置准备端：管理 API 批量开通、自助注册，或复用已开通编号。
func Provision(cfg Config, ids []string) error {
	if cfg.Reuse && cfg.AdminUser == "" && cfg.AdminPass == "" && cfg.APIToken == "" && cfg.RegisterCode == "" {
		return nil
	}
	if cfg.RegisterCode != "" && cfg.AdminPass == "" && cfg.APIToken == "" {
		return registerAll(cfg, ids)
	}
	if cfg.AdminPass == "" && cfg.APIToken == "" {
		return fmt.Errorf("开通端需要 -admin-pass / -admin-token，或 -register-code；复用已开通端请加 -reuse")
	}
	ac, err := adminLogin(cfg)
	if err != nil {
		return err
	}
	if cfg.Reuse {
		return createOneByOne(ac, ids, cfg.Password, true)
	}
	return importCSV(ac, ids, cfg.Password)
}

func adminLogin(cfg Config) (*harness.AdminClient, error) {
	base := cfg.adminBase()
	ac, err := harness.NewAdminClient(base)
	if err != nil {
		return nil, err
	}
	ac.HTTP.Timeout = 10 * time.Minute
	if cfg.APIToken != "" {
		ac.APIToken = cfg.APIToken
		return ac, nil
	}
	user := cfg.AdminUser
	if user == "" {
		user = "admin"
	}
	body, _ := json.Marshal(map[string]string{
		"username": user,
		"password": cfg.AdminPass,
	})
	resp, err := ac.PostJSON("/api/admin/login", body)
	if err != nil {
		return nil, fmt.Errorf("管理员登录: %w", err)
	}
	raw, _ := io.ReadAll(resp.Body)
	_ = resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("管理员登录失败: %d %s", resp.StatusCode, raw)
	}
	return ac, nil
}

func importCSV(ac *harness.AdminClient, ids []string, password string) error {
	for start := 0; start < len(ids); start += maxImportRows {
		end := start + maxImportRows
		if end > len(ids) {
			end = len(ids)
		}
		var b strings.Builder
		b.WriteString("id,name,login_password,talk_password,default_delay_seconds,remark\n")
		for _, id := range ids[start:end] {
			fmt.Fprintf(&b, "%s,%s,%s,,,\n", id, id, password)
		}
		resp, err := ac.Do(http.MethodPost, "/api/admin/endpoints/import", []byte(b.String()), "text/csv")
		if err != nil {
			return fmt.Errorf("批量开通: %w", err)
		}
		raw, _ := io.ReadAll(resp.Body)
		_ = resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			return fmt.Errorf("批量开通失败: %d %s", resp.StatusCode, raw)
		}
	}
	return nil
}

func createOneByOne(ac *harness.AdminClient, ids []string, password string, reuse bool) error {
	for _, id := range ids {
		body, _ := json.Marshal(map[string]string{
			"id":             id,
			"login_password": password,
		})
		resp, err := ac.PostJSON("/api/admin/endpoints", body)
		if err != nil {
			return fmt.Errorf("开通 %s: %w", id, err)
		}
		raw, _ := io.ReadAll(resp.Body)
		_ = resp.Body.Close()
		if resp.StatusCode == http.StatusOK || resp.StatusCode == http.StatusCreated {
			continue
		}
		if reuse && isTaken(resp.StatusCode, raw) {
			continue
		}
		return fmt.Errorf("开通 %s 失败: %d %s", id, resp.StatusCode, raw)
	}
	return nil
}

func registerAll(cfg Config, ids []string) error {
	base := strings.TrimRight(cfg.HTTPBase, "/")
	client := &http.Client{Timeout: 30 * time.Second}
	for _, id := range ids {
		payload, _ := json.Marshal(map[string]string{
			"registration_code": cfg.RegisterCode,
			"id":                id,
			"login_password":    cfg.Password,
		})
		resp, err := client.Post(base+"/api/client/register", "application/json", bytes.NewReader(payload))
		if err != nil {
			return fmt.Errorf("注册 %s: %w", id, err)
		}
		raw, _ := io.ReadAll(resp.Body)
		_ = resp.Body.Close()
		if resp.StatusCode == http.StatusOK || resp.StatusCode == http.StatusCreated {
			continue
		}
		if cfg.Reuse && isTaken(resp.StatusCode, raw) {
			continue
		}
		return fmt.Errorf("注册 %s 失败: %d %s", id, resp.StatusCode, raw)
	}
	return nil
}

func isTaken(status int, raw []byte) bool {
	if status == http.StatusConflict {
		return true
	}
	var env apiEnvelope
	if json.Unmarshal(raw, &env) != nil {
		return false
	}
	if env.Error != nil && (env.Error.Code == "id_taken" || env.Error.Code == "conflict") {
		return true
	}
	return false
}

func (c Config) adminBase() string {
	if c.AdminHTTP != "" {
		return strings.TrimRight(c.AdminHTTP, "/")
	}
	return strings.TrimRight(c.HTTPBase, "/")
}